Early on in our relationship I brought up to my gf that I would be interested in opening the relationship up and her having sex with someone. Well last weekend we were drinking and I asked her if she would take another cock and that I want to jack off while she's getting fucked and pleasure and take a load of cum in her pussy. She agreed and said she'd make it happen. Yesterday she brought up how she mentioned it to a guy she knows that has been Trying to get in her pants for a couple years now. He's not really on board with being watched and wants to fuck her at his place and send her back not being able to walk. But she thinks she can convince him to let me watch. I'm very excited but also nervous that it might actually happen. Any tips or advice for me for if/when it does actually happen?